The invention generally relates to a piston-type compressor and more specifically to an improved suction plate for a piston compressor.
In the case of piston-type compressors shown for example, in (German Patent Documents DE 39 04 172 A1 and DE 39 09 531 A1), suction plates are provided which have an essentially circular shape and, by means of their freely movable part, that is, the part which can be swivelled perpendicularly to the plane of the valve support plate, are adapted to the position of the suction apertures situated in the valve support. The recessed interior area of such suction apertures as well as partial areas outside their outer contours may be called a waste space since a waste volume remains in each case between the top side of the piston in its upper dead-center position and the underside of the valve support or of the valve support plate. The fitting-in of the suction plates takes place by pin elements or, when they are used on an energy saving system (German Patent Document DE 39 09 531 A1), by a toggle lever operating system which permits a displacement of the suction plate between two active positions, specifically the pumping position and the idling position.
Based on the above, it is an object of the invention to further develop a suction plate of the above-mentioned type, when using constructionally simple devices with respect to its fitting or fixing, such that the waste volume above the piston of the compressor is reduced to a minimum. Suction plates of this type must also be usable in energy-saving systems for piston-type compressors claiming the above-mentioned advantages.
The objects are obtained by a suction plate, which consists of an inactive section and an active section, and covers almost the whole cross-section above the piston of the compressor, that is, on the underside of the valve support. This results in almost no waste volume laterally to the active section in the upper dead-center position of the piston. The active section, which is preferably constructed as a tongue-shaped valve plate, and extends almost along the whole diameter of the plate disk body such that the two sides of the active section are limited by approximately semicircular inactive section sections with delivery apertures penetrating them.
The fixing of the suction plate takes place without additional mounting devices; that is, the suction plate can be inserted and clamped in between the cylinder and the valve support plate. For the purpose of a securing with respect to rotation, a notch is provided on the outer circumference of the suction plate, a projection on the cylinder or on the valve support plate engaging in this notch. The suction plate can also be advantageously used in the case of piston-type compressors with a so-called energy-saving system. As the result of their disk-shaped configuration, it can be rotated by a simple rotary drive in order to achieve a complete covering of the delivery apertures of the valve support or in order to achieve the desired partial opening of the suction apertures of the valve support.
Advantageous developments and further developments are listed in the claims.
In the following, the invention will be explained by means of embodiments with reference to the enclosed drawing.